Police are now frequently using location data stored by cell phone manufacturers or carriers to track users -- with or without warrrants. (Source: Thomas J. Henry)

The ACLU are fighting to force police departments to come clean about their tracking. (Source: Life After Life)

A new law could prevent police from tracking people without warrant, but it is opposed by the Obama administration. (Source: Law Enforcement Preparation)

Big Brother is tracking you?

Back in the 1990s, in order to track a cell phone you would have to triangulate the signal to its source -- an imprecise science that would merely put you "in the ballpark" of the caller. That all changed when GPS chips were added to today's smartphones.

I. The ACLU Expresses Concern About Police Location Tracking

The American Civil Liberties Union on Thursday announced [press release] a "massive coordinated information-seeking campaign", probing police use of location data in their investigations. In total 379 requests for information were filed under state freedom of information laws by 34 local chapters across the country.

GPS devices are typically a highly appreciated addition to cell phones, as they allow precise location-aware maps, turn-by-turn driving directions, and other "location aware" services. However, they are also used by companies like Google Inc. (GOOG) and Apple, Inc. (AAPL) to target advertisements at users.

It is apparent that they are increasingly being used by the police, as well.

No one knows exactly how many police departments use the technique. But it is clear that in at least some cases, tracking is a frequent engagement. South Brunswick, New Jersey's Police Chief Raymond Hayducka told the AssociatedPress in an interview, "Every week we get some kind of crime where we have to do some kind of tracking."

"It's done for a legitimate law enforcement purpose. There's no other reason to do it."

He says that the tracking was done with communications data warrants from a local judge. Police submit preliminary evidence to the judge in order to obtain the warrant. He says that tracking is also used in non-criminal cases to locate lost hikers or people who called 911 and hung up.

It is unclear, though, whether all police departments across the country that use tracking must get warrants to do so. And since records of the practice have not been made public, previously, in most departments that track, it's impossible to know whether abuses occurred.

Also unknown is which kinds of smart phones are susceptible to tracking. Both Apple and Google claim to anonymize any data they collect from their smart phone users. However, Apple in particular came under a firestorm of scrutiny when it was discovered it was storing a local cache of location data that covered the users' movements for the entire lifetime of the phone. Apple claimed the collection was accidental -- the result of a "bug" -- and issued a patch to remove the local caching feature from iPhones.

Carriers may also may be the ones collecting personally identifiable GPS data from users.

II. "The Public Has a Right to Know"

The ACLU is most upset about the lack of transparency with tracking programs. Catherine Crump, staff attorney for the ACLU Speech, Privacy and Technology Project, states, "The ability to access cell phone location data is an incredibly powerful tool and its use is shrouded in secrecy. The public has a right to know how and under what circumstances their location information is being accessed by the government. A detailed history of someone's movements is extremely personal and is the kind of information the Constitution protects."

Some departments -- including the South Brunswick Police Department -- have already expressed their willingness to share the requested information with the ACLU. The ACLU says it will use the data to assess the amount of money spent on smart phone tracking, whether warrants were used, and how frequently tracking occurred.

Currently there's no national law banning explicitly warrantless cell phone tracking, so its suspected many police departments are engaging in such a practice. Many feel such tracking violates the protections of the Fourth Amendment of the Constitution, which states:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

The Fourth Amendment puts forth the criteria that searches must be "reasonable" and that warrants must only issued in the case where "probable" cause is suspected. Particularly important, some argue, is the final half of the sentence, which suggests that warrants must "particularly" describe the place to be searched.

Most privacy advocates feel that warrantless tracking blatantly violates protections against unreasonable searches and the freedom of people to be "secure in their persons, houses." When it comes to warranted tracking, many believe it's still illegal because police typically don't know exactly what they're looking. Advocates argue that warrants should not be granted in many cases as police don't describe "particularly" what they're watching for as the Fourth Amendment mandates, instead engaging in a more sweeping campaign of violations to a person's privacy.

Of course, as no law bans warranted or warrantless tracking, such opinions only have legal power to stop tracking programs if they are affirmed at various levels in the court system. A Supreme Court ruling could directly lay to rest the debate, but so far the highest court in the U.S. has not directly ruled on the issue.

Some relief may be on the horizon. Congress is currently debating the Geolocation Privacy and Surveillance Act (GPS Act), which has the backing of the ACLU. The GPS Act would require warrants be issued to track citizens. It would also require that citizens consent to telecommunications companies collecting location data.

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